Optical elements having variable, i.e. controllable, optical properties are used in many applications. One example of such an optical element is a zoom lens arrangement, where the focal length and therefore the field of view is generally varied by moving individual lenses of the zoom lens arrangement relative to each other. Such zoom lens arrangements are for example used in photography.
Other optical elements with variable properties comprise variable reflectors, i.e. mirror arrangements comprising a plurality of individual mirrors at least some of which are movable to change the optical properties of the system. Such variable reflectors are for example used in flash devices for photography.
The above-mentioned conventional variable optical elements, depending on the implementations, may be comparatively bulky. On the other hand, for example in the field of photography an increasing miniaturization has taken place. For example, digital cameras including a flash light are often incorporated in mobile phones, with considerable space restraints.
Therefore, it would be desirable to have variable optical elements which are more compact than conventional elements.